It is important to identify your niche before you start to make money online because this is where you're going to concentrate so that you will not lose focus and you keep tab of your performance so easily and the niche could be in graphic designing, web development, marketing, writing etc.
It is very important that when it comes to identifying a niche which you are going to be making money online from, you should try as much as possible to have something that is your passion being the anchor. This is because that is the only way you will not give up on it when it becomes challenging.